Correct the returned UDP datagram length.  See the PR for a more comprehensive description of the fix.
Correct the returned UDP datagram length.  See the PR for a more comprehensive
description of the fix.

PR:		misc/25503
Submitted by:	Jim Browne <jbrowne@jbrowne.com>
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase